The Arabidopsis LATERAL ORGAN BOUNDARIES-domain gene ASYMMETRIC LEAVES2 functions in the repression of KNOX gene expression and in adaxial-abaxial patterning

Plant Cell. 2003 Oct;15(10):2241-52. doi: 10.1105/tpc.014969. Epub 2003 Sep 24.


The normal development of lateral organs of the shoot requires the simultaneous repression of meristem-specific genes and the activation of organ-specific genes. ASYMMETRIC LEAVES2 (AS2) is required for the development of normal leaf shape and for the repression of KNOX genes in the leaf. AS2 is a member of the recently identified, plant-specific LATERAL ORGAN BOUNDARIES (LOB)-domain gene family. Expression of AS2 at high levels resulted in repression of the KNOX homeobox genes BREVIPEDICELLUS, KNAT2, and KNAT6 but not of the related SHOOT MERISTEMLESS gene. Overexpression of AS2 also led to a perturbation of normal adaxial-abaxial asymmetry in lateral organs, resulting in the replacement of abaxial cell types with adaxial cell types. These results indicate that AS2 is sufficient to induce adaxial cell fate and repress KNOX gene expression.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Arabidopsis / genetics*
  • Arabidopsis Proteins / genetics*
  • Base Sequence
  • DNA Primers
  • Gene Expression Regulation, Developmental
  • Gene Expression Regulation, Plant*
  • Homeodomain Proteins / genetics*
  • Plant Leaves / physiology
  • Plant Structures / physiology
  • Plants, Genetically Modified
  • Repressor Proteins / genetics*
  • Transcription Factors / genetics*


  • AS2 protein, Arabidopsis
  • Arabidopsis Proteins
  • DNA Primers
  • Homeodomain Proteins
  • KNAT2 protein, Arabidopsis
  • Repressor Proteins
  • Transcription Factors